Wireless communication systems have evolved in a way of increasing data rate for meeting the gradually increasing wireless data traffic demand.
The research and development activities for the 4G systems have been focused on the improvement of spectral efficiency to increase data rate, but the exponentially growing wireless data traffic demand may not be met through only spectral efficiency improvement.
One approach to solve this problem is to use a very broad frequency band which cannot be secured in the frequency spectrum (<5 GHz) in use by current cellular mobile communication systems but can be secured in higher frequency spectrum.
Meanwhile, the higher the transmission frequency, the greater the radio wave propagation loss. The increased radio wave propagation loss decreases wave propagation distance, resulting in reduction of service coverage. Therefore, there is a need of a method and apparatus for transmitting/receiving signals efficiently in a broadband frequency.